Generating a range of integers in a query

Hello,

I've got an interesting problem: I need to select all possible values
of an attribute that do /not/ occur in the database.

This would be easy (in my case at least) if there were a way to
generate a table containing all integers between 1 and n, where n is
the result of a subquery.  In my case, n will be at most a few
hundred.  I would like to be able to generate this table as a
subquery.  Any ideas?

Thanks,

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Aaron Bingham
Senior Software Engineer
Cenix BioScience GmbH
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